The present invention relates to a canine pre-proGHRH polypeptide, a caninemature GHRH peptide, an isolated polynucleotide which encodes the canine pre-proGHRH or the canine mature GHRH. The invention also encompasses vectorsencoding and expressing the canine pre-proGHRH or the canine GHRH which can beused to treat disease and growth hormone deficiencies by gene therapy invertebrates, in particular in dogs.